Process of inlaying sheet material and the products thereof



Jan. 22, 1952 5 5 00 2,583,396

PROCESS OF INLAYING HEET MATERIAL AND THE PRODUCTS THEREOF Filed Jan.10, 1949 PER F. SKOOG Zmnentor Patented Jan. 22 1952 PROCESS OF INLAYINGSHEET MATERIAL AND THE PRODUCTS THEREOF Per F.Skoog, Olympia, Wash.

Application January 10, 1949, Serial No. 70,125

J. My present invention relates to a process of inlaying sheet materialand the products thereof, and, more particularly, is the provision of anovel method of patching wood veneer and the patched veneer and plywoodproducts resulting from said method.

The description of my invention as to its use in the plywood industrywill be employed herein for purposes of exemplification. It will beapparent, however, that the invention will have application in otherways well within the abilities of those skilled in the field of sheetmaterial production and ornamentation. I

In the prior art of patching veneer sheets, it has been usual to cut outthe damaged part of the sheet so that there is an opening with eitherstraight sides, or sides which slopeinwardly from the face of the sheet;A patch is formed of a configuration that is intended to be the same asthe opening so that when the two are fitted together the walls of theopening will contact the walls of the patch. However, a close fit hasnever been fully obtainable. In order to practice the process of theprior art, it was necessary for the patches to be very accurately cut toclosely fit the opening in the veneer sheet. If the work was notproperly done, as i usually the case, the fiber ends of both thepatch'and the sheet would buckle upwardly and show on-the face of thesheet. This is particularly true where the fibers have been cut at moreor less right angles to the grain of the sheet. Gaps around the patchwould occur which requires -a second step of patching. In many cases theresulting prior porduct, even after sanding, had a surface which wasunsightly, which would not take stain or paint in an even manner, and inwhich the patch was most obvious, thus rendering the finishing of thesurface diflicult and unsatisfactory. At this time the face patching ofquality veneer and plywood is practically unknown or so expensive as notto be economically possible.

Having in mind these and'other defects of the prior art, it is among theimportant objects of this invention to provide a process of inlayingsheet material, of which veneer is 'a good example, so that the inlayedpiece is practically invisible; a process that, is economically usablein the inlaying or relatively low-cost sheet material for the purpose ofup-grading the same and making it more valuable in industry; a processwhich, in the woodworking industry, permits a greater use of the lessperfect products of the forest in the manufactured veneer and plywood aprocess which issimple andea'sy to per- 4 Claims. (01. 2o-s9) form andmay be practiced with a modicum of equipment and relatively unskilledlabor; and a. process of patching veneer for overlaying and plywood usesin which there is a feathering of the edges of the patch so that thesame may be sanded and finished and will blend with veneer without theformation of a distinct and apparent line of juncture in the sheetmaterial. Other objects include the provision of a novel veneer and anovel plywood as products in industry and characterized by havingsuperior face qualities without the requirement that they be producedfrom superior products or with the employment of great skill and laborto overcome surface defects in the exposed face.

The defects mentioned above in the prior art are remedied, and theforegoing objects are attained by forming in a sheet of veneer, forexample, an opening which is flared and has sloping walls. Assuming oneparticular face of the sheet to be that to be exposed, the openingflares from that face toward the other face. through the sheet, whichmeans that the edges of the opening on the face side of the sheetoverhang. A flare-edged patch similar in configuration to thethree-dimensional area of the opening is formed and positioned so thatthe smaller face of the patch and the smaller end of the opening areadjacent each other, and the slope of the patch is opposite the slope ofthe walls of the opening. In this relation the larger face of the patch,which is that that will be exposed in the face of the veneer, is offsetfrom the veneer sheet and the smaller face if the patch is facing theveneer face. The patch and opening are axially aligned. An adhesivematerial i applied .between the edges of the patch and the veneer thatit will contact, and the patch is pressed to the veneer to cause the twoelements to assume a coplanar relationship. Such pressing forces .theoverhanging edges of the veneer around the opening to be deflected sothat the face fibers of the veneer around the opening lie along theslope of the patch walls, or, to put it another way, the opening isreversed. When the adhesive has set, the pressure is removed and theveneer has been patched. After the veneer has been glued onto anotherlayer of wood (crossband) the routed section of the sheet under thepatch, as well as the exposed center portion of the patch, is firmlybonded to the crossband and held in line therewith. Subsequent sandingof the face of the veneer whenin place on a backing structure removesoutstanding fibers of the patchand feathers the .patch edge onto theveneer face so as to substantially hide the patch in the grain of theveneer. By careful selection of the material for the patch and veneer asto the matching of the grain between the two, invisible patching ispossible.

The process described briefly above and the products of this inventionare illustrated in the accompanying dravn'ng, in which Figure 1 is adetailed view illustrating the manner of forming an opening in a sheetto be inlayed;

Figure 2 is an enlarged sectional view, taken along the fiber or grainof the sheet, and showing a patch positioned for insertion into thesheet;

Figure 3 is a sectional view similar to Figure 2 showing the patch inplace in the sheet; I

Figure 4 is a sectional view of plywood sheet having a face ply patchedor inlayed according to my invention;

Figure 5 is a perspective view of a veneer sheet patched accordin tothis invention and having parts broken away and shown in section forconvenience of illustration; and

Figure 6 is a plan View of the broad face of a boat-shaped veneer patch.

While inlays of various shapes may be obtained according to thisinvention, since its application is described in connection with its usein the plywood and veneer industry, I have found that the boat-shapedpatch having double convex edges and either pointed or slightly roundedends is most desirable since it blends well with grain structure and isthe most simply produced and used. However, it will be apparent thatfrustoconical patches and diamond shaped patches are also entirelypossible and, under certain circumstances, desirable or useful.

I have shown in Figure l the manner in which the veneer sheet is cut toprovide the desired opening. The sheet I is placed on a table 30 havingan opening 32 over which the defect of the sheet is oriented prior tocutting. Cutter-head 34, suitably rotated, is mounted on arm 36 to swingabout the axis of crank pin 38, to which is attached lever that isconnected by link 42 to foot pedal 44. A spring 46 will serve to returnthe cutter head. Preferably, the cutters 46 of head 34 are V-shaped andare ground to an angular relationship to the plane of table 36 that isdesirable for the particular veneer being inlayed.

It will be understood that the showing of Figure 1 is schematic as otherequipment is contemplated, and it will be quite obvious that the cuttingof the veneer can be a manual operation employin the most simple handtools.

In Figure 2 is shown a sectional view of a sheet of wood veneer havingan elongated opening therein to be patched and, adjacent to the opening,a matching patch for insertion therein. The sectional view is takenalong the longitudinal fibers of the sheet and patch. The opening in thesheet may be of any suitable form, either round or boat-shaped,boat-shaped being usual in the patching of veneer. The veneer sheet I isconsidered to have a face 2 and a back 3. The opening in the sheet hassloping walls 4 which flare from the face 2 to back 3. The angles whichthe walls of the opening make with the face of the sheet is not criticaland vary between 5 and but in Douglas fir veneer I have found that anangle of 15 is most practical to use. The patch 6 for the opening has aface I and a back 8 with sloping edge Walls 9. The angle which the faceof the patch makes with the sloping walls 7 is generally equal to theangle which the face of the sheet makes with the walls of the opening.It is to be observed that if the back of the patch is placed in theplane of the face of the sheet, the walls of the opening will intersectthe edge walls of the patch on the line of the sheet face opening, andthat the face of the sheet will be a bisector of the angle formed by theintersection of said walls. If the angle of the walls of the openingvaries around the opening, then the angle of the walls of the patchshould vary in the same manner around the patch, so that the face of thesheet continues to be a bisector of the intersecting walls; that is, theacute angle of the edge of the opening will be substantially the same asthe acute angle of the edge of the patch. The patch is formed with thesame conformation as the opening to be filled, with the exception of theslope of the patch edge-wall being inward from the face I, whereas theslope of the opening wall is outward from the face of the sheet.Generally, the patch is cut so that its grain will lie parallel to thegrain of the sheet.

Insertion of the patch in the opening is had, first, by bringing thepatch into registry with the opening as shown in Figure 2 and applying asuitable adhesive to the walls of the patch and around the opening.However, the adhesive may be applied before bringing the patch intoregistry. Second, the patch is then forced into the opening in anysuitable manner, as by the use of pressure platens that may be heatedwhere thermoplastic or thermosetting adhesives are used. This forcing ofthe patch into the sheet opening will bend the sheet fibers overhangingaround the opening, downward so that the fibers of the face around theopening will lie along the sloping wall of the patch, and the end of thesheet fibers at the opening will show on the back side of the sheet.This condition is shown in Figure 3.

The turning down of the edge of the opening of the sheet insures thatthe ends of the sheet fibers will not show on the face and will aid infeathering the edge of the patch. It is to be understood that the veneerfibers at the side of the patch, which have not been cut in making theopening, will not have ends showin on the back side of the sheet. Thiscondition is illustrated at In in Figure 5, where the patch has beenshown partly broken away after having been inserted in the veneer. Theuse of suitable heated platens and adhesives will set the adhesiveapplied to the patch and sheet so that, at the end of the patchingoperation, the patch will be securely held in place, as shown in Figure3. However, if the adhesive is a slow setting adhesive, the plywoodsheets may be left in the press or placed in a stack with other sheetsunder pressure until the ad hesive has set.

Following insertion of the patch, the face of the sheet and patch may besanded to remove any surface roughness, and to feather the edges of thepatch. This sanding and further feathering of the edges of the patch aidin obscuring the glue line between the patch and sheet but will notuncover fiber ends of the sheet, as often happens in the prior artpatching process.

Figure 4 shows a veneer sheet I I having there in a patch I2 inserted inthe manner of the present invention and, incorporated with the filler,or core, I3 and backing veneer I4, the three sheets form a plywoodsheet. When a veneer sheet, patched in accordance with the presentinvention, is incorporated properly in aplywood 5 sheet, the end fibersof the free face l5 of the sheet adjacent to the patched opening arehidden and buried against the core stock I3.

Ordinarily, it is desirable that the patch inserted into the veneersheet not be pressed in farther than to align with the back face 3. Itis even possible to secure excellent results where the patch is onlypartially inserted, since any cavity thereunder is usually filled withadhesive when the veneer is layed up into plywood or on a piece of corestock. The important consideration is that the face of the patch liesslightly above the face of the sheet so that when sanding of the sheetis had, the patch Will be cut down to the level of the sheet. Whilesanding is best practiced when the veneer has been mounted on a core orstiff backing, it is also possible to perform the same on the relativelythinner veneer sheets.

It has been found that, in finishing sheets processed in accordance withthe present inven tion, they take stain, paint, varnish, or othersurfacing materials much better and more evenly than do the prior artsheets, as there are none of the ends of the sheet fibers exposed andonly a very few ends of fibers from the patch exposed.

Having thus described my invention, I claim:

1. A patched veneer sheet having secured in an opening therein aflat-faced patch having substantially normal and undistorted cell andgrain structure and having its edge walls cut to flare from the back tothe face of said veneer sheet; the face of said patch being positionedsubstantially in the plane of the face of said sheet and the back ofsaid patch being positioned substantially in the plane of the back ofsaid sheet: the walls of said opening being formed of grain structureintegral and originally coplanar with the face grain of the veneer sheetand bent to lie along said walls of the patch, and being tensed to pressagainst said walls of the patch; and the portion of said veneer sheetforming that surface of the back immediately bordering said patch lyingsubstantially in the same plane as the rest of the back of the veneersheet and being formed of material originally constituting the walls ofan opening in said veneer sheet which flared from the face to the backof said veneer sheet.

2. Ihe product of claim 1 in which the patch n is boat-shaped and theopening in the veneer conforms thereto.

3. A plywood assembly in which a face veneer sheet is patched by havingsecured in an opening in the veneer sheet a flat faced patch havingsubstantially normal and undistorted cell and grain structure and havingits edge walls cut to flare from the back to the face of the veneersheet; the face of said patch being positioned substantially in theplane of the face of said sheet and the back of said patch beingpositioned substantially in the plane of the back of said sheet, and theportion of said veneer sheet forming that surface immediately borderingsaid patch lying substantially in the same plane as the rest of the 6back of the veneer sheet and being formed of material originallyconstituting the walls of an opening in said veneer sheet which flaredfrom the face to the back of the veneer sheet the walls of the firstmentioned opening being formed of grain structure integral andoriginally coplanar with the face grain of the veneer sheet and bent tolie along said walls of said patch and being tensed to press againstsaid well of the patch, and said patch being adhesively bonded at itsinner face to the veneer sheet of said plywood assembly next underlyingsaid face veneer sheet.

4. In the art of disguising defects in wooden veneer sheets by Woodenpatches, the method, comprising: forming an opening in a wooden veneersheet in an area having a defect so as to remove the defect and aportion of the veneer sheet therearound, the forming of the openingbeing conducted when said area is in its natural, undistorted positionin said sheet and before the patch is placed in the position it is tooccupy in said sheet, said opening being formed with walls flaring fromthe face to the back of said sheet; forming separately a patch with aface, back and sloping walls having substantially the same shape andsize as said opening but with the walls converging from the face to theback of said patch when the patch is in a natural, undistortedcondition; placing said patch in a position off-set to the face of saidsheet and in registry with said opening with the slope of the Walls ofsaid patch and said opening directed opposited and nonparaliel and withthe back of said patch on the side thereof towards said sheet and withthe face of said patch on the side thereof away from said sheet; andthen, lastly, pressing said patch toward said sheet to wedge the sameinto said sheet and opening to cause the face of said sheet adjacentsaid opening to be deflected toward the back of said sheet to lie alongsaid patch walls and forcing said flaring walls of said opening to liegenerally in the same plane as the back of said sheet and with the faceof said patch generally lying in the plane of the face of said sheet andwith the back of said patch generally lying in the plane of the back ofsaid sheet, said patch remaining substantially undistorted, andadhesively bonding said patch in place.

PER F. SKOOG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 256,567 Holmes Apr. 13, 18821,498,545 Fox et a1 June 24, 1924 1,703,890 Loetscher Mar. 5, 19291,878,081 Welch Sept. 20, 1932 2,175,654 Alenius Oct. 10, 1939 2,536,665Skoog Jan. 2, 1951

